1. Field of the Invention
The present invention relates to an optical switch including a micro electro mechanical system mirror array (MEMS mirror array) utilized in an optical communication system.
2. Description of the Related Art
EP 1 102 096 A2 discloses a conventional optical switch. This optical switch will be described with reference to FIG. 12.
The optical switch has one set of a fiber lens array and a MEMS mirror array on an input side, and another set of a fiber lens array and a MEMS mirror array on an output side.
The fiber lens array 903 on the input side has an input fiber array 901 and an input lens array 902 corresponding thereto. The MEMS mirror array 905 has tilt variable mirrors 904a arranged like fibers 901a. The input fiber lens array 903 and the MEMS mirror array 905 are arranged to be opposed to each other, and the fibers 901a and the tilt variable mirrors 904a correspond to each other in a one-to-one relationship.
Likewise, the fiber lens array 913 on the output side has an output fiber array 911 and an output lens array 912 corresponding thereto. The MEMS mirror array 915 on the output side has tilt variable mirrors 914a arranged like the fibers 911a. The input fiber lens array 913 and the MEMS mirror array 915 are arranged to be opposed to each other, and the fibers 911a and the tilt variable mirrors 914a correspond to each other in a one-to-one relationship.
An exiting beam 921 projected from an input fiber 901a strikes the tilt variable mirror 904a opposed to the input fiber 901a, being converged by an input lens 902a. The tilt variable mirror 904a is allowed to be inclined about rotational axes. For example, as the variable tilt mirror 904a is inclined so that a reflection angle of the beam 921 is to be θa shown in the drawing, the beam 921 is reflected toward the tilt variable mirror 914a of the MEMS mirror array 915. The beam 921 is further reflected by the tilt variable mirror 914a to be directed to an output fiber 911a. 
Therefore, by changing angles of the tilt variable mirrors 904a of the MEMS mirror array 905 on the input side and the tilt variable mirrors 914a of the MEMS mirror array 915 on the output side, an optical switch which can lead an optical signal from an arbitrary input fiber 901a to an arbitrary output fiber 911a can be realized.